Sunny,
You have already shown a great deal of common-sense in seeking advice from this forum. Even a one-day course will clarify things further. Such a short course will not give you the competency to check all matters relating to a FRA, but it should give you the competency to say to your bosses "I am not competent in these certain areas, we need to call in outside help."
For example, you could probably sit down with a plan of the school, the relevent documents and check exit widths and travel distances and say "Yes, the means of escape are adequate" or "No, they are not." But you are unlikely to be able to say "The fire alarm system is adequate/inadequate." because you don't have the expertise (and possibly the equipment) to do so. Likewise aspects of the structural fire precautions; for example, are suspended ceilings (if you have any) correctly fire-stopped where they should be?
Hope this helps you.